Self-adjusting coupling for bridge-chords and stay-rods



(N0 Madel.)

W. IRELAN.

SELF ADJUSTING COUPLING FOR BRIDGE CHORDS AND STAY RODS.

No. 307,770. 7 Patented Nov. 11, 18 84.

TED wns PATENT rricla WILLIAM IRELAN, or OAK SPRINGS, IOWA.

SELF-ADJUSTING COUPLING FOR BRIDGE-CHORDS AND STAY-RODS.

SPECIFICATION forming part 01' Letters Patent No. 307,770, dated November 11, 1884:.

Application filed April 7, 1884.

T0 aZZ whom it may concern.-

Be it known that I, WILLIAM IRELAN, of Oak Springs, in the county of Davis and State of Iowa, have invented a Self-Adj ustin g Coupling for Bridge'Ghords and Stay-Rods, of which the following is a specification.

My object is to prevent the dangers, accidents, and loss of life and property occasioned by the unequal expansion and contraction of metal chords and rods in bridges, and their consequent breaking, and the falling of bridges when under heavy pressure of loaded wagons and cars.

My invention consists in the construction and combination of coupling-bars having pins extending eccentrieally from their opposite ends with beams or rods having eyes at their ends, as hereinafter fully set forth, in such a manner that the bar will be turned by the expansion or contraction of any one beam or red connected therewith as required to produce snug tight joints, to maintain an equal tension on all the connected rods and their tensile strength combined, and to resist any strain to which a chord or complete bridge may be subjected.

Figure l of my accompanying drawings is a side view of a section of a bridge, showing my self-adjusting chord-coupling in use. Fig. 2 is a top view showing four beams adj ustably connected by means of one coupling-bar. Fig. 3 shows a section of chord in which eight rods and beams are adj ustably combined by means of' one of my coupling-bars. Jointly considered, these figures clearly illustrate the construction and operation of my complete invention.

' A is a metal bar, that has pins B projecting from its opposite ends and on opposite sides of the longitudinal axis of the complete revolving bar. The ends of the pins are screwthreaded. By simply slipping the revolving bar and its pins into the overlapping eyes of metal beams, and then placing nuts on the (No model.)

ends of the pins, the beams or rods required to form a chord are adjustably connected in such a manner that if they are not of exact equal length or are subjected to unequal eX-. pansion or contraction the coupling-bar will revolve a fractional part of a revolution, to equalize the tension of all the beams or.rods connected therewith and relieve any one piece of undue strain; and when all the pieces are thus automatically adjusted and the complete chord subjected to heat orcold it will lengthen and shorten as required to maintain a uniform tension of all its pieces by the self-adjusting motions of the coupling-bars having the pins on their ends eccentrically located relative to the centers of motion of the complete bars.

My coupling may be advantageously used at the top or bottom. of a bridge, or wherever tension or stay rods are combined.

I am aware that a bolt or pin having a head at one end and a screw at its opposite end has had eccentrics on its body to engage the eyes of rods, but not to fill the eyes, as required to produce tight joints. My coupling-bar having pins projecting from its opposite ends and on the opposite sides of the longitudinal axis of the bar, and adapted to fill the eyes of rods and to secure snug tight joints in the complete chord, is therefore novel and greatly advantageous in connecting and adjusting four or more beams or rods in a bridge.

I claim as my invention-- A couplingbar, A, having pins B on its opposite ends and on the opposite sides of its longitudinal axis, in combination with four or more beams or rods having eyes at their ends adapted to admit the said pins B, for the purposes specified.

\VILLIAM IRELAN.

XVitn esses J. P. GASTOX, 'l. J. Foo'rn. 

